The invention relates to a pattern mechanism for a knitting machine, particularly but not exclusively for a flat knitting machine.
In such pattern mechanisms, needle control means are provided comprising pattern sinkers, which can be lowered into and raised from a needle bed, or a cylinder in the case of cylindrical knitting machines, by means of pattern levers, or which can be moved in the direction of movement of the needles. The feet of the pattern levers, or of the pattern sinkers movable in the direction of the needles, are in staggered formation. The pattern levers, at each passage of a selection point on a cam, are lowered to the needle bed or the cylinder and held either in, or half in or fully out in accordance with the particular pattern by control members, and the pattern sinkers movable in the direction of the needles are controlled by lifting control members.
In known pattern mechanisms, pattern selection proceeds by arranging a tipping sinker or a pattern lever to be pivoted so that the foot of the pattern sinker which slides on the pattern lever, either disappears into the needle bed, or half or fully projects therefrom, whereby it can be caught by the cam means at different heights so that the needles selectively form meshes or loops or do not operate. The size of the pattern field depends upon the number of pattern sinkers or pattern levers, which are in mutually adjacent staggered formation. The number of feet in different positions staggered transverse to the needle bed is then limited by the width of the needle bed in flat knitting machines, and by the height of the cylinder in circular knitting machines.
A similar dependence of the number of feet on the size of the pattern field exists also in pattern mechanisms for knitting machines in which the pattern selection takes place by location behind the needles of pattern sinkers with staggered feet, which are movable with the needle in the direction of movement thereof and thus in a common plane.
In a second type of known knitting machine pattern mechanism, which operates with pattern sinkers, cam elements are introduced by means of magnets between the feet of the pattern sinkers or pattern levers arranged successively in the direction of cam movement. In that case also the knitting speed depends inter alia upon the number of the feet arranged in staggered formation.
In flat knitting machines in which the selection points in both travel directions of the carriage are situated at various postiions on the cam, it is necessary to provide, for each travel direction of the carriage, corresponding cam parts with associated electromagnets, which means doubling the number of the cam members and electromagnets. Finally, all the known pattern mechanisms have the disadvantage that there must be provided for transfer cams individual selection points with associated actuating devices.
The present invention has for an object the provision of a pattern mechanism of the first described type, which is simple and compact in construction.
The invention also has as an object the provision of a knitting machine pattern mechanism which ensures correct needle operation in accordance with a selected pattern, for all knitting and transfer operations which occur, by means of simply operated control members.